Brian Eno teamed up with neuroscientist Mendel Kaelen to create an app for therapeutic music - and it ended up expanding both their minds

The last time I dropped acid alone was fourteen years ago, and I swore I'd never do it by myself ever again.

But a few weeks ago, I spent ten hours alone with a blindfold over my eyes, headphones capped over my ears and LSD molecules plugged into my brain, listening to music in solitude. I'd done LSD plenty of times, but never blind and motionless. I wasn't worried I'd freak out - I thought I would go crazy with boredom. Instead I found myself crying cathartic tears for so hard for so long, I had to use two blindfolds because the first became soaked through.

I was testing a new form of technology that combines generative music - a style of music that is made not by a strict set of instructions like with sheet music, but by a set of rules that allow for ever-changing creations - with AI software being developed by musician Brian Eno and neuroscientist Dr. Mendel Kaelen from London's Imperial College.

"The surprises you get with an experience of generative music are gentle - not in the music, but in what happens to you, the listener," Eno tells Rolling Stone. He and Kaelen want everyone to be able to have the kind of experience I just did, with or without drugs.

While shutting myself in a room alone with just an iPhone for company was not my idea of a good time, it was necessary to understand the experience of using the app, called Wavepaths, which Kaelen unveiled at the Horizons psychedelic science conference in New York earlier this fall. Eno, Kaelen and a small team of psychotherapists and AI specialists already have seed funding from the European Institute of Innovation & Technology (EIT). The idea has been brewing for a year - now Eno and Kaelen are going public with the concept, looking to gather collaborators and funding.

Kaelen's formal pitch: "Using immersive art, psychotherapeutic techniques, and intelligent technologies, Wavepaths provides new ways to become more intimate with ourselves and others, to listen to what our emotions are telling us, to explore what can be discovered in the depths of our own minds, and to drive meaningful changes in our personal lives."

Perhaps the idea of giving people transformative experiences with a smartphone sounds odd, but the intention is to create experiences that are anything but trite. "The last thing we want is for people to think is that the app will provide funny or weird experiences," says Kaelen.

One form of the app will be for the public, and another with additional features will be available to professional psychotherapists who use music in their work. Plus special versions customized to certain drugs - such as MDMA or psilocybin - will be available for clinical work using psychedelics.

The idea of using music as medicine is hardly new; professional therapists already use music in scientifically tested formats to treat conditions like anxiety, depression and autism. Nor is the concept of psychedelic therapy new: psychiatrists widely deployed LSD in legit settings in the 1950s to patients ranging from institutionalized mental patients to Hollywood stars. Cary Grant - coping with the trauma of being abandoned by his mother at eleven - called the experience "an immeasurably beneficial cleansing".

Over the past decade, countless clinical trials have demonstrated the capacity for combining these contraband chemicals with therapy sessions to treat a huge range of ailments, from MDMA for PTSD and psilocybin for addiction to LSD for depression and ayahuasca for eating disorders.

And the idea of mixing music with LSD as a legit medical therapy isn't new either - in fact, before the hippies got their hands on the it, LSD was legally deployed by psychiatrists in the 1950s to work through trauma, depression and addiction. Shrinks would dose blindfolded patients with the drug, play classical music and ask gentle questions to prompt introspection. Hundreds of people experienced this form of therapy at legit institutions in Europe and North America before it leaked from the lab out into the counterculture.

The difference with Wavepaths is that the app will create unique musical scores tailored to every listener based on their tastes and psychological needs, such as the need to calm anxiety, or to soothe rage. Artificial intelligence software and generative music algorithms will create the music but the interface will be responsive, so users (or their therapists) will be able to alter the flavor of the music on the fly. Plus the app will gather data from users, and using machine learning, build repertoires of musical modes and spectrums. It will learn over time which musical settings users like the most - both what individual people like, but also what's popular with everybody. The musical library will constantly evolve.

Put it all together, and you get a seventy-year-old idea - musical psychedelic therapy - brought back to life using modern technology. "It is very gratifying to see the world once again waking up to the power of psychedelic therapy. We hope it's only a matter time before it returns to mainstream medicine, and when it does, we want therapists to have the right tools for the job," says Amanda Feilding of the Beckley Foundation, who has worked in psychedelic research for forty years and who funded Kaelen's PhD.

Music therapists in the twentieth century adhered to the belief that certain kinds of music were inherently more therapeutic or nourishing than others - mostly classical and western music - and many developed strict playlists not to be deviated from. In therapy, whether music should be chosen by the listener or prescribed by the counsellor - human or mechanical - is a matter of debate.

"I sit in the middle of the debate - I don't think there's a problem with using music that you have already been exposed to, but if music is unsettling, you should have the capacity to change it," says Dr. Charles Grob of UCLA, who researches how MDMA can treat trauma and how psilocybin alleviates anxiety in terminal-stage cancer. "Mendel is very gifted in adapting music to psychedelic experiences, and he is working with a world-class musician, so I'm excited to see what they do."

Eno will curate the soundscapes, and composers Gregory Haines, Jon Hopkins, Laraaji, Robert Rich and Steve Roach are already on board. Eno says he also plans to include the "godfathers" of generative muOf Canada, and Aphex Twin.

The key is that all the music will be a hundred percent generative - what Eno describes as "self-evolving compositions". Generative music can be created by a machine, a computer, a human orchestra, or at its simplest level a set of wind-chimes: it's created by a system that is set in place, and then let to play itself and evolve on its own. No two recreations made using that system will ever be the same.

Eno made the term "generative" famous with his 1978 album Music For Airports, which he originally designed as a sound installation using several continuous loops of tape of varying lengths played on a number of speakers, set to run in an airport terminal. Eno was not the only musician creating such compositions - Terry Riley's In C is one of the best-known. A simple set of instructions, it is designed to be played by humans - modern performances have featured classical musicians, students at the Royal Irish Academy Of Music using synthesizers, and an orchestra from Mali at the Tate Modern in London, with Blur's Damon Albarn.

But when computers are used instead of humans or tape reels, songs can produce themselves for theoretically infinite lengths of time - important considering an acid trip can last eight hours or more. Crucially, the music provided by Wavepaths is designed to be "incommensurable" - unlikely to ever be repeated. This ensures there is no chance that a familiar song - one that reminds you of a dead parent, lost friend, or ex-lover - could crop up and hijack your experience.

"Generative music is deliberately 'discreet' - it doesn't try to grab your attention, but instead invites you into itself," says Eno. "That can be very welcome in a world where everything else is trying to grab you by the lapels and make you pay attention."

Though Music For Airports was a total flop when it came out - dismissed by critics as "muzak" - some people understood what he was trying to do with this new style, today termed "ambient".

"David Bowie once told me that he listened to nothing other than the [1975] album Discreet Music during a three-month period when he was touring and struggling with drugs," says Eno. "The music is so calm and slow that it induces a similar calmness in listeners." (Incidentally, when Bowie was in his 1978 recovery phase in Berlin, Eno co-wrote the track "Heroes".)

Eno also discovered that hospitals were using Discreet Music in birthing rooms for the same reason Bowie loved it during his tumultuous time: the sense of calm. Now his work on generative music has found new life in the age of touch screens: apps such as Bloom and Reflection, created with musician and software designer Peter Chilvers, allow anyone to carry their own tool for creating self-evolving music in their pocket.

On a tablet or smartphone screen, Bloom behaves like the flat surface of a pond - at first there are no sounds, but touch the screen and a note is created, replaying itself every few seconds, the volume decreasing with every subsequent note. Ripples that emanate outwards from wherever you touch the screen trigger notes anywhere else you touch the screen - a bit like the audio effect of throwing pebbles repeatedly into a pond. It is designed to never play the same thing twice - and it is eerily soothing. Autistic children, Eno tells me, tend to be particularly fond of Bloom. This app was released in 2008 - other apps followed, most recently Reflection, which features even more interactive features, and is designed to make subtly different music throughout the time of day and year.

Wavepaths takes it a step further - it's designed explicitly as a therapeutic tool. In the same way that guided mediation apps like Headspace and Insight Timer aim to help people learn new ways to relate to their own thoughts, Kaelen and Eno hope to build listening exercises into Wavepaths to help people develop new ways to listen to music.

"When you allow yourself to be deeply touched and fully moved by music, then music can carry you beyond the boundaries of your daily sense of self - and you can see your life from a new perspective," says Kaelen. "What we have learned from both psychedelic therapy research, introspective music therapy formats and deep-listening practices, is the power of fully surrendering to an experience of art."

As for the psychedelic side of things, Eno says as "a non-experimenter", he'd never considered the possibility of using music in combination with drugs until he met Kaelen.

Kaelen - to put it mildly - knows a thing or two about psychedelics. He has spent the past five years as part of the research team that last year published the world's first brain-scanning study that revealed what happens in the brain under the influence of LSD. "The world waited seventy years for this," says lead author Professor David Nutt, director of the Neuropsychopharmacology Unit at Imperial. "It was the most difficult study I've ever gotten approved."

In the simplest terms possible, the study found that LSD causes "increased connectivity": regions of the brain that wouldn't normally communicate suddenly babble at one another.

Or, as Kaelen's colleague in psychedelic research, Dr. Robin Carhart-Harris, once explained to me: "Taking a psychedelic is like shaking up a snow-globe."

Why should the combination of music and psychedelics be so intense?

"The human brain is a highly hierarchically organised system," says Kaelen. "Psychedelics allow regions that process emotions and memories to do so more freely. And then there's music, which directly activates these regions. So in the temporarily absence of the usual control systems, this may explain why we observe such profound interactions between psychedelics and music. Vivid recollection of personal memories, strong emotions and new perspectives"

For now, the app is the first step - but that will take some years to develop. However next year as a "taster" for what it will feel like: sound installations created by Eno in London, featuring samples of what will appear on the app. For decades, Eno has created sound and light installations in spaces ranging from museums to hospitals - a hundred and fifty designs so far.

"These spaces in London will be where immersive art and psychotherapy meet to give people access to personally meaningful experiences in a secular context and embedded in real-life human communities," says Kaelen. "We believe in the power of art to facilitate life-changing experiences, independent of your world-views."

Though the final app will take a while, in the meantime there's a playlist Kaelen crafted for a clinical study that used psilocybin for depression. It features many of the same musicians that have signed up already to work on Wavepaths, such as Max Richter, Robert Rich and Brian Eno.

A neuroscientist in London tells me she tried out using that playlist with LSD and a blindfold. Though she has studied the neuroscience of psychedelics for years, and done them recreationally many times, she never experienced anything like doing it blind. "People put way too much emphasis on the visual aspects of psychedelics - seeing pink elephants or whatever - and pay far too little attention to the emotional and cognitive effects," she says. "I really found that once you took away the visual input, then you could really experience what's going on."

And she was right: I've done LSD plenty of times, but it never felt like this. The physical sensations were unlike anything I'd ever experienced - especially from the music itself, which uncannily felt like it was speaking to me directly. As weird as it sounds, it felt like it was holding me in its arms and telling me everything was going to be ok.

Kaelen tells me this is actually a common experience with music therapy: "Music has the capacity to give people the sensation they are being heard." I understand now why Kaelen calls music, "the hidden therapist".